A shift from cars to more active modes of travel will also decrease traffic in congested city centres and help reduce air pollution, with further benefits for health
A very strange comment.
If a multi-occupancy car changes to multiple cycles that is an increase in traffic.
If the comment is meant to say an increase in congestion in city centres, then there would need to be a very large reduction in car numbers in order to compensate for the increased congestion caused by creating bike lanes.